Re: Flint life
With a proper lock and flint, they can last to 100 shots. I personally have gotten more than that with a well tuned lock on a smooth bore trade gun.
Flints breaking can be caused by poor lock geometry, improper placement of the flint or even by case hardened frizzens that are starting to wear through the hard layer. TC makes what is generally a first rate gun, except for their flint locks. the quality of the frizzen steel should be better, so they don't need to be case hardened.
A quality lock, like an L&R can be fired hundreds of times without showing grooves and marks on the frizzen face.
Optimum flint locks have a special angle to hold the flint as well as an arc that maximizes striking the arc of the frizzen face to throw lots of sparks.
I prefer the dark gray English flints. But I pick them out myself. Hold them up to the light and inspect for cracks. Make sure they are a uniform translucent color with no muddy areas. I can pick though five or ten flints for every one I choose. It makes a difference in the life of the flint. Don't just buy something on a blister card at Walmart and expect long life.